New glow plugs, barely starts now.

[young-gunn]

had a bit of a rough start issue, found I had one dead glow plug. I had been using bosch plugs for an older north american 2lt for a while as the proper ones were hard to find here. ordered and installed NGK y715r or whatever the part number is. the old ones worked but didnt last too long. Now when I start the truck it barely wants to start. This problem started as soon as I put the new glow plugs in. Fuse is good, can hear the relay click. Getting 10.5 volts to the plugs, then drops to 7.5 or so when the reay clicks off, then 0 after 10 more seconds or so. I changed my fuel filter thinking it was bad fuel, same problem. The truck cranks and I have to give it throttle then it fires with a cloud of black smoke from the tailpipe. all fluids are clean and at a good level. no bubbles in the coolant, no fuel leaks, no vacuum in the tank. I've tested the new glow plugs and they all test at .4 ohms or so. I've unhooked the batteries and let it sit in an effort to allow the computer to re-learn the new plugs. I've also changed injectors in the past 2 months and it's been runnimg good since. just noticed a problem as soon as I put the new plugs in. this is my only vehicle at the moment so I really need to figure something out quick :/ Any ideas?

[J20]

If you still have the old plugs, you could try swapping them back in to eliminate the new ones from the list of possible faults. (Possible bad batch?). Other than that, check that all the connections have been reassembled correctly.

Check the fuel lines around the new filter. The rubber hoses could be perished if they haven't been renewed. I don't know how this would give black smoke but it's something to check.

Also, there is a thread somewhere on the forum about the causes of different colours of exhaust smoke (white, grey, blue, black). That might give you some ideas.

[mickyod]

Have you blocked off your EGR?
Mine used to kick out black smoke until I blocked the EGR off.

Try cycling the ignition a couple of times then start might help but obviously isn't solving the problem.

Sure someone with more knowledge will be along shortly👍

Mike

[young-gunn]

I think I'll put the old glow plugs in today and give that a try. yesterday I tried to fire it up before I went to sleep without allowing the plugs to cycle and it didn't want to fire, the engine was still a little warm to the touch but not very warm so I didn't really expect it to start. cycled the glow plugs and it fired up instantly so they do seem to be working. thinking maybe something else is at fault and just happened to totally fail at the same time? maybe a temperature sensor somewhere? is it the one under the intake that has something to do with starting? is there a way to test my sensors with a multi meter or anything? My fuel lines were all replaced last year when I fixed my problem with fuel running back to the tank. my egr is blocked off with plates. This problem seemed to be minor for a while but once I put the new glow plugs in it was really a problem. I usually have to cycle the glow plugs a few times as I only crank it for 5 or 10 seconds then shut it off to give the starter a chance to cool down. I moved recently and this is the only vehicle I have out here so I really need to repair this asap.

[young-gunn]

I've been checking as much as I can, testing sensors, checking for fuel leaks, bleeding the fuel system and I haven't found much. My intake air temperature sender has been laying in my engine bay for years as I have made a ram air intake and never drilled a hole to put it in my custom intake. I tested it and I have 5volts to it, but no resistance through it, shouldn't this have resistance unless it is burnt out? Also, could someone post a picture of the temperature sensor that adjusts the fuel put in at start up? I see one above my starter but it is quite far below the intake plenum, I assumed it would be tucked right up in there from what I've read.

I put my old glow plugs back in and we'll see how she feels in the morning. I have no check engine light on but I will check codes tomorrow just out of curiosity. I tested the old glow plugs and the resistances vary a fair bit but they do all still show resistance. The new glow plugs are removed but still testing .5 ohms. It sat 4 hours after I got home from work (it's about -10 celcius here right now) and I just tried to start it and it fired up immediately after one glow plug cycle.

[young-gunn]

Sorry to bump this again but I really need to sort this out as it's my only vehicle out here and I'm already wishing I didn't have to deal with this. Plugged in it seems to start okay. Glow plugs seem to be working fine as well though. Injectors are new, fuel stays primed. This has to be a sensor problem. I have a new air temp sensor coming as I'm not finding any resistance through mine and I imagine there should be resistance. the temp sensor above my starter has been broken for years but I may order a replacement anyway. I'm not getting any codes from the truck. I'm really running out ideas, nothing that ever goes wrong with my truck seems to be simple.

[shokenore]

Does the truck start ok when/if the engine is warm?
Are you using straight diesel?

[J20]

The sensor above the starter is the block coolant sensor. This feeds back to the ecu and should cause a red check engine light on the dash if disconnected or faulty. At least it did on mine when I knocked the connection loose.

You should have a fault code for this I would think? If not I would wonder why and suspect ecu connections or some other issues with feedback to/from the ecu. There is a way of running a live diagnostic with the engine running that might give more info.

[J20]

Does the truck start ok when/if the engine is warm?
Are you using straight diesel?

Is there a fuel pre-heater on your truck and is it working? The pre-heater is on the fuel filter mounting I believe (not fitted to mine).

[young-gunn]

My truck does not have a fuel pre-heater.

[J20]

Have you seen this link?

In the article, "normal mode testing" is with the vehicle parked up and "test mode testing" is the live diagnostic.

Also, for more info, have a look through the technical articles on this link on the same site.

[J20]

My truck does not have a fuel pre-heater.

You can get one from any place that sells Surf bits. I don't know if it is pre-wired for though so you might need to wire it in yourself.

I wouldn't be convinced this is your problem, but it couldn't hurt to have one in those Canadian winter temperatures.

Milners in the UK sell them.

[shokenore]

So
Does it start easier when warm?

[young-gunn]

Sorry been working and didn't see that first post. truck starts fine warm and this morning was plugged in at -20 and fired up instantly with one glow plug cycle. Short cloud of black smoke but it went away right away with no misfire. The truck is straight piped so it's pretty normal for it to smoke a bit. Ran the diagnostic test yesterday and only got only code 11, trans not in park. went away when I stopped driving. I haven't thrown any sensor codes at all even though that temp sensor is physically broken. I'm getting a new sensor today and my air temp sensor is in the mail, could get that today too.

[shokenore]

If the glow plug sequence is timing out correctly as indicated by your previous post then it sounds like your glow plugs might be dodgy
Btw what engine oil are you using?